SELECTIVE METAL TO CARBON BOND FORMATION IN THE SYNTHESIS OF THE 1ST RHENIUM COMPLEXES WITH S2CPCY3 LIGANDS - X-RAY STRUCTURES OF [MNRE(CO)6(MU-S2CPCY3)] AND [RE2(CO)8(MU-S2CPCY3)]

Reactions of either [Mn(CO)3(S2CPCy3)(Br)] with Na[Re(CO)5] or [Re(CO)3(S2CPCy3)(Br)] with Na[Mn(CO)5] produce selectively the heterobimetallic complex [MnRe(CO)6(mu-S2CPCy3)], which contains an unsymmetrical eta-2(S,S'),eta-3(S,C,S')-S2CPCy3 bridge donating eight electrons with the carbon atom of the S2C group bonded to manganese; in contrast, the reaction of [Re(CO)3(S2CPCy3)(Br)] with Na[Re(CO)5] produces [Re2(CO)8(mu-S2CPCy3)], with a eta-1(S),eta-1(S')-S2CPCy3 bridge of four electrons and no carbon-rhenium bond. In apparent contradiction with previous theoretical predictions, all the experimental facts suggest a stronger ability for managanese, when compared to rhenium, to become attached to the carbon atom of the S2CPCy3 ligand.